1. Field of the Invention
The present invention relates to a solid-state imaging device, a method of manufacturing the same, and an electronic apparatus.
2. Description of the Related Art
Solid-state imaging devices are broadly classified into two representative kinds of solid-state imaging devices of a CCD (Charge Coupled Device) image sensor and a CMOS (Complementary Metal Oxide Semiconductor) image sensor. In recent years, in the CCD image sensor or the CMOS image sensor, since the size of a pixel decreases and the number of photons incident on a unit pixel decreases, sensitivity deteriorates and thus a decrease in S/N occurs. In widely used pixel arrangement where red, green, and blue pixels are arranged on a planar surface, for example, the Bayer arrangement using the primary color filters, green and blue light does not penetrate a color filter in red pixels and is not used in photoelectric conversion. Therefore, sensitivity may decrease. Moreover, when a color signal is formed by executing an interpolation process between pixels, a problem of a false color may arise.
In order to solve these problems, Japanese Unexamined Patent Application Publication No. 2007-12796 discloses a solid-state imaging device in which green, blue, and red photoelectric conversion units are laminated in a depth direction of the same pixel. In the solid-state imaging device, a blue photodiode (photoelectric conversion unit) and a red photodiode (photoelectric conversion unit) are formed in the depth direction in a silicon substrate. In addition, the solid-state imaging device includes an organic photoelectric conversion unit in which a green organic photoelectric conversion layer interposed between electrodes is formed on the upper layer of the front surface of the silicon substrate on the side of a light incident side with a wiring layer interposed therebetween. According to the configuration disclosed in Japanese Unexamined Patent Application Publication No. 2007-12796, since a light loss does not occur in the above-mentioned color filter, the sensitivity is improved. Moreover, since the interpolation process is not performed between pixels, a false color does not occur.
Japanese Unexamined Patent Application Publication No. 2008-258474 discloses a back-illuminated CMOS image sensor including color filters, a photoelectric conversion unit with photodiodes laminated in a depth direction, and an organic photoelectric conversion layer. The solid-state imaging device disclosed in Japanese Unexamined Patent Application Publication No. 2008-258474 includes the color filters arranged in yellow and cyan check pattern. The photoelectric conversion unit formed by the red and blue photodiodes is disposed in correspondence with the yellow and cyan filters. Moreover, an organic photoelectric conversion unit is disposed in the upper layer of each photodiode. The solid-state imaging device takes out a green signal from the organic photoelectric conversion unit, takes out a red signal from the photodiode of the yellow filter, and takes out a blue signal from the photodiode of the cyan filter.